5 Soy Crop Diseases: Ensuring Crop Health in the Midwest USA

Soybeans and corn collectively occupy roughly three-quarters of the Midwest's agricultural land, spanning more than 125 million acres. Given the vital role these crops play in our food supply, it is essential for farmers and agricultural advisors to be well-prepared for possible disease outbreaks.

The Midwest is especially prone to several soilborne diseases caused by bacteria and fungi, which seriously endanger soybean yields. Among many critical soybean diseases detected by BeCrop® Technology, several notable diseases identified in the Midwest include Sudden Death Syndrome, Frogeye Leaf Spot, Charcoal Rot, White Mold, and Pythium (Damping Off).

Top 5 Soybean Diseases

• Sudden Death Syndrome: This disease, caused by Fusarium virguliforme, manifests as root rot and foliar symptoms. Early detection and proactive management are crucial for mitigating its impact on soybean production.
• Frogeye Leaf Spot: Caused by Cercospora sojina, this disease results in circular lesions with a gray center on soybean leaves. Monitoring for symptoms and timely application of appropriate biocontrols can help control its spread.
• Charcoal Rot: Macrophomina phaseolina is the culprit behind Charcoal Rot, affecting soybean roots and stems, leading to charcoal-like discoloration and yield reduction. Implementing proper crop rotation and soil health management practices can help minimize its impact.
• White Mold: Sclerotinia sclerotiorum causes White Mold in soybeans, characterized by white mycelial growth and sclerotia formation on stems. Practices such as maintaining adequate spacing between plants and promoting airflow can aid in disease prevention.
• Pythium (Damping Off): Various Pythium species can cause damping-off in soybeans, particularly in cool and wet conditions. Implementing well-draining soil and avoiding over-watering can help mitigate the risk of Pythium infection.

Preventive Measures and Management Strategies

Early detection, proactive management, and preventive measures are essential for mitigating the adverse effects of soybean diseases. Implementing the following strategies can help safeguard soybean crops:

• Predictive Soil Analysis: Biological soil analysis can provide insights for early detection and timely intervention, particularly before visible disease symptoms.
• Resistant Varieties: Planting soybean varieties with genetic resistance to specific diseases can provide an added layer of protection.
• Crop Rotation: Rotating soybeans with non-host crops can help break disease cycles and reduce pathogen pressure in the soil.
• Biocontrol Application: When necessary, careful use of biocontrol inputs can help manage disease outbreaks and minimize yield losses. A wide range of commercial biofungicide products are available on the agriculture input market, and they typically have far shorter restricted entry intervals and pose less of a threat to beneficial soil biology than conventional chemical fungicide products can. 

Possible Treatments and Control Mechanisms

Sudden Death Syndrome caused by Fusarium virguliforme

Sudden Death Syndrome in soybeans, caused by Fusarium virguliforme, results in root rot and foliar symptoms, significantly impacting yield. To control this disease, soybean growers can implement crop rotation with non-host plants like corn or wheat to reduce pathogen survival. Additionally, using resistant soybean varieties when available can help mitigate the disease's impact and protect crop yield.

Frogeye Leaf Spot caused by Cercospora sojina

Frogeye Leaf Spot, caused by Cercospora sojina, leads to circular lesions with a gray center on soybean leaves. To manage this disease effectively, farmers should rotate crops to break the disease cycle and reduce inoculum levels. Applying biocontrols preventatively during early reproductive stages is also recommended to control Frogeye Leaf Spot and minimize its impact on soybean plants.

Charcoal Rot caused by Macrophomina phaseolina

Charcoal Rot affects soybean roots and stems, causing charcoal-like discoloration and reducing yield. To prevent Charcoal Rot, it is advised to plant soybeans in well-drained fields to minimize disease development. Avoiding excessive irrigation and minimizing soil compaction are essential practices to reduce the incidence of Charcoal Rot in soybean crops.

White Mold caused by Sclerotinia sclerotiorum

White Mold in soybeans, caused by Sclerotinia sclerotiorum, manifests as white mycelial growth and sclerotia formation on soybean stems. To control White Mold effectively, growers should utilize wider row spacing to improve air circulation and reduce humidity levels favorable for the pathogen. Additionally, applying biocontrols preventatively during flowering stages can help manage and prevent White Mold in soybean fields.

Pythium (Damping Off) caused by various Pythium species

Pythium (Damping Off) is a common issue for soybeans in cool and wet conditions. Farmers should focus on improving soil drainage to prevent Pythium infection to avoid waterlogging promoting Pythium growth. Planting soybeans in well-drained fields and avoiding overwatering are crucial steps to reduce the risk of Pythium-related damping-off in soybean crops. Biocontrol seed treatments may also be explored. 

By conducting a biological soil analysis to identify the microbial communities and their interactions with Pythium species, soybean farmers can effectively tailor their biocontrol strategies. This knowledge can guide the selection of appropriate biocontrol seed treatments that work synergistically with the existing soil microbiome to combat Pythium infections and enhance soybean crop resilience.

Prevention and Soil Health in Soybean Crops

BeCrop biological soil analysis for soybean crops can provide valuable insights into disease prevention, soil health management, and sustainable agricultural practices. By utilizing BeCrop, farmers can make informed decisions to protect their soy crops from prevalent diseases and optimize crop productivity. The analysis can help identify soilborne bacterial and fungal diseases that may affect soy crops, allowing for proactive measures to prevent and control these diseases effectively.

See below a sample report where several diseases above were detected early from a single soil sample

Protecting soybean crops from diseases requires a proactive approach that combines preventive measures with effective management strategies. By understanding the nature of these diseases and implementing appropriate control methods, soybean farmers can safeguard their crops and ensure sustainable production. Incorporating biological soil insights into farm management practices can help optimize crop health and productivity, contributing to the long-term success of soybean cultivation in the Midwest.

Note: Biome Makers’ agronomists have identified some of the top soilborne bacterial and fungal diseases affecting crops in the US. These diseases are mentioned in the soil. While not all soilborne diseases are included, the selected ones are among some of the most impactful, with variability by region. It's important to note that the diseases are not listed in order of impact, and they do not include viruses. The detection of these diseases is made possible by BeCrop technology and soil database, offering valuable insights for crop management and disease prevention.